Blindstitch attachment for sewing machines



Nov. 9, 1965 v. J. SIGODA 3,215,384

BLINDSTITCH ATTACHMENT FOR SEWING MACHINES Filed June 21, 1963 3 Sheets-Sheet 1 'IIIIIIIIIIIIIIIIIIIIIA I m 'VENTOR.

fi fi Nov. 9, 1965 v. J. SIGODA 3,216,384

BLINDSTITCH ATTACHMENT FOR SEWING MACHINES Filed June 21, 1963 3 Sheets-Sheet 2 INVENTOR. 0,014. 14cm d. 5/6004 ill. I! I VIII/III I.\ WI

Nov. 9, 1965 v. J. SIGODA BLINDSTI'ICH ATTACHMENT FOR SEWING MACHINES 3 Sheets-Sheet 3 Filed June 21, 1965 INVENTOR. Moro c). 5/6004 i rro/P/vc'y United States Patent Office 3,216,384 Patented Nov. 9, 1965 3,216,384 BLINDSTITCH ATTACHMENT FOR SEWING MACHINES Victor J. Sigoda, Great Neck, N.Y., assignor to Man- Sew Corporation, New York, N.Y., a corporation of New York Filed June 21, 1963, Ser. No. 289,616 8 Claims. (Cl. 112-140) This invention relates to bindstitching attachments for use with sewing machines either of the double needle or the single needle zigzag type, for applying an infolded fabric strip, tape, braid or piping to the surface of another base or carrier fabric for ornamental purposes. Such attachments are commonly known as blindstitch facing attachments in the trade.

The attachment is in the form of a replacement for the usual presser foot and consists of a main shank portion and a folder portion. Previously these have been permanently joined together so that the folder assembly could not be removed for substitution of another folder assembly to accommodate either wider or narrower strips or for replacement in case of damage or wear. In the improved attachment, the shank portion by which the entire attachment is applied to the presser foot bar, is provided with a large opening or window through which an improved fabric strip folder extends to feed the fabric strip from the rear of the machine forwardly to and around a blindstitching nose adjacent the needle path. Although in previous constructions the blind-stitching nose has been made positionally adjustable with respect to the needle path, the folder assembly has been of fixed construction and therefore not positionable with respect to the needle path. In the arrangement disclosed herein the shank portion supports a presser shoe carrier which is shiftable, and this carrier not only supports the presser shoe but the folder assembly as well.

As previously made, the blindstitch nose has been a fixed edge over which the folded fabric strip is bent for needle penetration. The improved construction includes a low friction nose in the form of a roller supported in the presser shoe over which the folded fabric strip is blindstitched.

In the earlier constructions, the folder assembly has had to be specially and artfully contrived for particular fabrics and for particular weights and Widths of such fabrics. In the improved folder assembly automatic compensating features have been provided which eliminate much of the art required for successful fashioning of the folder and which make a particular folder capable of handling a wider range of widths and weights of strip fabrics than heretofore. These features also permit the passage of thickened sections such as cross seams which occur in bias cut and subsequently joined fabric strips without choking of the folder.

Another feature of the improved attachment is the provision of a compact strip tensioning means which is capable of fine adjustment to provide a considerable range of strip tensions.

Accordingly it is the main object of the invention to devise a blindstitch facing attachment having the features of construction and arrangement indicated above to bring about better and more economical production of such blindstitching. Other objects will either be obvious or will be pointed out in the following detailed description taken in conjunction with the drawings herein in which:

FIG. 1 is a front elevational view of a typical sewing machine on which the improved attachment has been installed;

FIG. 2 is a sectional view of the attachment taken on lines 22 of FIG. 1;

FIG. 3 is a perspective view of the attachment as it appears before being attached to the presser foot bar of the sewing machine;

FIG. 4 is a plan view of the folder assembly;

FIG. 5 is a perspective view showing the progressive infolding of the edges of the fabric strip during its passage through the folder and indicating the relative position of the roller nose in the presser shoe and the threaded needle just before the beginning of the blindstitch penetration by the latter of the infolded fabric strip;

FIGS. 6, 7, 8, 9, 10 and 11 are respectively sectional views taken on lines 6-6, 77, 88, 99, 10-10 and 1111 of FIG. 2 showing the structure of various portions of the folder members and the manner in which they progressively produce the infolding of the edges of the fabric strip as shown in FIG. 5; and

FIG. 12 is an exploded perspective view showing the various parts of the attachment disassembled but in the same relative positions as when assembled.

The sewing machine designated 1 is a standard Singer zigzag sewing machine having the usual presser foot bar 2 on which the attachment generally designated 3 is supported. The attachment may be conveniently divided into a shoe and folder support assembly 4 and a folder assembly 5. The reciprocating needle 6 is carried by the usual needle bar and operated by well known needle reciprocating and lateral vibrating mechanisms.

Referring to FIG. 3, shoe and folder support assembly 4 has a shank portion 10 by which the attachment is mounted on the presser bar 2. Shank portion 10 has a substantially rectangular opening or window 11 and a rearwardly extending projection 12 which, as shown in FIG. 2, inclines upwardly and is internally threaded to receive a manipulatable thumb screw 15. A large fillister head screw 16 is mounted on the underside of the shank portion.

Shoe carrier 18 has an internal T-slot 19 (see FIG. 12) which fits over the head of screw 16 with just enough clearance so that the carrier can be bodily shifted horizontally along the underside of the shank portion. Carrier 18 also has a stub extension 20 against which coil spring 21 (see FIG. 2) mounted in recess 22 of the shank portion, bears when carrier 18 is mounted as shown in FIG. 2. Since spring 21 normally urges carrier 18 against the cone point 24 of thumb screw 15, appropriate manipu lation of screw 15 will cause carrier 18 to shift in either direction with respect to the path of the needle 6. Spring 17 retained under the head of screw 15 maintains it in adjusted position against unintended rotation due to vibration, etc.

As seen in FIG. 12, carrier 18 has a pair of ears 25 pierced with internally threaded holes, and a depending projection 26 from either side of which a pair of flat shoe supports 28 extend. As seen in FIG. 3, ears 25 support the folder assembly 5 and the presser shoe 30 is carried by supports 28. Because of its construction shoe 30 is readily demountable and therefore may be replaced when Worn or damaged. More importantly, it may be removed for substitution by another shoe of different size or configuration to suit the width or other requirements of variout different types of fabric strips or tapes which are to be sewn.

As shown in FIG. 12, shoe 30 has a pair of upstanding lugs 31 each of which is slotted horizontally. Ends 32 of the upper portion of each of these slotted lugs may be bent downwardly slightly as shown to provide tension to hold the shoe in place when snapped onto supports 28 or some alternate means for fixing the shoe in place on supports 28 may be utilized. The forward portion of the shoe is split to provide a passageway 33 for the reciprocating needle 6 and the thread carried thereby, and roller 34 is mounted transversely in this passageway immediately adjacent the needle path.

The folder assembly 5 includes a U-shaped channel member 4% having a pair of ears 41 by which the channel member is demountably supported on carrier 18 and attached thereto by screws 42, with the channel member extending through window 11 of the shank portion as shown in FIGS. 2 and 3. Channel member 40 has a pair of spaced, upstanding walls 43, the configuration of which is shown in FIGS. 2 and 4. Between these channel sidewalls, folder tongue 44 is pivotally mounted by means of a tubular cross member 45 which is afiixed, as by soldering or welding, to the upper surface of tongue 44 near the inlet end 46 thereof (see FIG. 2). Cross member 45 is internally threaded at each end (see FIG. 8) to receive mounting screws 47 which pass through in register, clearance holes in each of the side walls 43. This arrangement permits cross member 45 to rotate about a horizontal axis passing through screws 47.

A second tubular member 48 is also mounted between the channel sidewalls by means of screws 49 which pass through in line openings or vertical slots in walls 43. If these openings are of slot form, then the position of the tubular cross member may be adjusted upwardly =or downwardly with respect to the bottom of channel member 40 to accommodate the requirements of different thickness fabrics which may be passed through the folder for blindstitching. Tightening of screws 49 will maintain cross member 48 in the selected fixed position, and unlike cross member 45, cross member 48 is not intended to rotate. Midway between its ends, cross member 48 is pierced with a threaded hole in which adjusting screw 50 is retained. The lower end of screw 50 bears upon the inlet tongue end 46 and hence turning screw 50 will cause tongue 44 to rock about its pivotal mounting. Spring 51 disposed between the head of screw 50 and the body of cross member 48 prevents any unintended movement of screw 50.

It will be seen that as screw 50 is threaded downwardly, the outlet end 52 of tongue 44 will rise, leaving more space between tongue end 52 and the bottom of the channel member 40. Such adjustment limits the downward movement of tongue end 52. Because of the pivotal arrangement, tongue end 52 may however move upwardly, the extent of such upward movement being limited by the clearance between inlet tongue end 46 and the bottom of the channel member (see FIG. 2).

Cross member 48 also supports two fingers 54 and 55 which cooperate with tongue 44 to bring about the progressive infolding of the edges of the fabric strip in its passage through the folder. The effect of these fingers is best shown in the sectional views FIGS. 9, and 11. Tongue 44 and fingers 54 and 55 are made of thin, resilient and hence flexible, material-s such as either spring steel or nickel silver which provide desirable yieldable characteristics which contribute to the automatic accommodation of these folder members to varying bulk in the fabric strip passing through the folder.

Fingers 54 and 55 are anchored at their upper ends to cross member 48 by means of screws 56, with the free ends extending downwardly toward the outlet of the folder. For a distance from their anchorages, fingers 54 and 55 are of relatively narrow width to provide resiliency which permits the fingers to rise vertically or to be displaced laterally as required momentarily by changing bulk in the passing fabric strip.- At 58 these narrow sections widen and the edges thereof 59 are curled (see FIG. 9) and provided with downwardly ex tending tabs 60 which fit into slots 61 in the bottom of channel member 40. Beyond tabs 60, the curled edges 59 continue to the extremities 62 of the fingers with second downwardly extending tabs 63 which fit into slots 64 in the bottom of the channel member (see FIG. 11). In an alternate form, tabs 60 and 63 may be combined into a single continuous tab fitting into combined slots 61 and 64 of corresponding length.

Slots 61 and 64 are relatively wide being several times the width of the thickness of tabs 60 and 63 to permit independent lateral displacement of fingers 54 and 55 when required by any momentary increase in the bulk of any particular portion of the infolding fabric strip passing under either of the fingers. To permit this independent action while retaining the infolded strip on tongue end 52, the ends 62 of the fingers are arranged in superposed relations as shown in FIG. 11.

To feed the infolded strip to the needle 6 for blindstitch penetration, the lower tongue end 52 terminates just above the roller 34 in the shoe 30 closely adjacent the needle path. As pointed out, adjustment of thumb screw 15 will position both the roller 34 and tongue end 52 suitably with respect to the needle path with micrometric nicety to accommodate the bulk of various inf-olded fabric strips for proper blindstitch penetration.

Successful infolding of the edges of the fabric strip requires that a specific amount of tension be applied to the strip as it is fed through the folder and this amount of tension varies from fabric to fabric. To provide a readily adjustable, compact means for furnishing various degrees of tension, the folder assembly includes tension guides arranged in a particular way. A pair of tubular tension guides 70 and 71 extend through corresponding circular openings 72 in sidewalls 43 of the channel member (see FIG. 2). These guides are held in spaced relation across the channel member by a pair of finger grips 74 to which the outer ends of guides 70 and 71 are secured as by screws 75. Guides 70 with finger grips 74, frictional engagement with the outer surfaces of walls 43 is sufficient to maintain the guides in adjusted position. When tubular guide 70 is disposed with respect to tubular guide 71 as shown in FIG. 2, tension will be applied to the fabric strip passing over the guides 70 and 71 and a similar stationary tubular guide 76 positioned near the inlet of the folder. By manipulating the finger grips to rotate guides 70 and 71 in a counterclockwise direction, guide 70 could be disposed in such position with respect to guide 71 that it would be possible to lock the strip against movement through the folder. By rotating the guides in a clockwise direction suficiently, they could be aligned with respect to each other so that the fabric strip would pass through without any tension being applied. Any desired degree of tension between these extremes may therefore be simply obtained by appropriate manipulation of finger grips 74.

In operation, a fabric strip is drawn (by the action of the feed members acting on that portion of the infolded and blindstitched strip which is passing between the sole of the shoe and the toothed surface of the feed dog) from a suitable source of supply mounted at the rear of the sewing machine and passed through the tensioning members 76, 70 and 71, adjusted for the desired tension, and thence through the channel member 40. As the strip passes under and then under and around tongue 44, and between tongue 44 and fingers 54 and 55, its longitudinal edges will be progressively inf-olded until they overlap as in FIG. 11. The infolded strip will emerge from the outlet of the folder wrapped around lower tongue end 52 and pass off the tongue end over roller 34 and bend around the roller to pass under the sole of the shoe. In this bent over attitude, the overlapped strip will be presented to needle 6 for blindstitch penetration, either with or without a base or carrier fabric also passing under the sole of the shoe. The desired depth of penetration by needle 6 within the folds can be obtained by suitable positioning of roller 34 with respect to the needle path by manipulation of thumb screw 15.

Whenever a bulky section of the strip is encountered, fingers 54 and 55 will yield either upwardly or laterally, or both, as required to accommodate the bulk, and after passage thereof, because of the inherent resiliency, the

fingers will each return to its initial position. This position is determined by the selected height of tubular guide 48 above the bottom of the channel member 40. Similarly the position of tongue 44 above the bottom of the channel member is fixed by the setting of screw 50. Since the tongue is flexible, passage of a bulky section between the bottom of the channel member and the tongue will cause the yieldable portion of the tongue to move upwardly to accommodate such bulk, and fingers 54 and 55 will be raised through the fabric between the fingers and the tongue. If the bulky section appears between the top surface of the tongue and the fingers, the tongue may move downwardly as the fingers move upwardly. Thus while these folding members continue in intimate contact with the strip, the contact will be temporarily disengaged as required to accommodate occasional bulky sections occurring in the infolding strip. Because these members are yieldable, fabrics of different weights or thicknesses may be accommodated within the same folder. Because previous folders could not accommodate such a range of thicknesses, and because the folder was integrally attached to the shank portion in such previous constructions, replacement of the entire attachment by a similar attachment was necessary. Since in this device the folder may be easily demounted, only a difierent folder is required rather than a complete attachment. Similarly, since the shoe is readily demountable, it likewise can be replaced by a more suitable member, rather than substituting a complete attachment. Such features there-fore greatly increase the usefulness of such attachments.

While the presently preferred embodiment has been disclosed and described in detail for the purpose of illustration, it is to be understood that the invention is not to be limited to the details of construction shown and described but it to be construed broadly within the spirit and scope of the appended claims.

What is claimed is:

1. An attachment for a sewing machine for the production of blindstitching in conjunction with the stitchforming and feed mechanisms of the sewing machine, said sewing machine having a presser foot-bar, said attachment comprising: a shank portion adapted to be mounted on the presser foot-bar, said shank portion having a large opening or window provided therein; a carrier movably mounted on the shank portion for positional adjustment with respect to the stitchforming mechanism when the attachment is mounted on the presser footbar; means associated with said carrier for demountably supporting one of a series of different capacity folders on the carrier; means associated with said carrier for supporting for quick detachment one of a series of different sized blindstitch-nosed shoes; each of said folders when supported by said carrier being movable therewith to pass freely through the window in the shank portion, and each of said shoes when supported by said carrier being movable therewith, said folder and said shoe being arranged in fixed adjacency when mounted on the carrier which adjacency is not affected by any subsequent positional adjustment of the carrier with respect to the stitchforming mechanism when the attachment is mounted on the presser foot-bar.

2. An attachment as in claim 1 in which the means for quickly detaching each of said shoes comprises a pair of spaced supports extending from said carrier and similarly spaced resilient clamping means associated with each of said shoes, the clamping means on each of said shoes being adapted to engage and be retained on the said supports.

3. An attachment as in claim 1 in which each of said folders includes a pivotally mounted tongue about which a fabric strip passing through the folder may form, the end of said tongue being positioned immediately adjacent the blindstitch nose in any of said shoes when one of said folders and one of said shoes are mounted on said carrier.

4. An attachment according to claim 1 in which the folder has an inlet and an outlet and in which the folder includes a channel having sidewalls; and in which means are provided at the inlet of the folder for applying tension to a fabric strip passing through the folder, said tension being adjustable, the tension means comprising a first tubular member supported transversely of the channel between the sidewalls thereof at the folder inlet, and a pair of additional tubular members rotatably supported transversely between said sidewalls, said pair of tubular members being manually adjustable with respect to the first tubular member.

5. A fabric strip folder for use with a sewing machine, said folder having an inlet and an outlet and comprising a longitudinally extending channel having a bottom surface and a pair of integral, upstanding coextensive walls continuously rising from said bottom surface; a longitudinally extending tongue pivotally mounted near the folder inlet between the channel walls on an axis transverse thereto, said tongue having longitudinal edges around and about which the opposed edges of a fabric strip in passing through the channel may be progressively infolded, and a pair of independently yieldable fingers extending longitudinally in the channel, said fingers being shaped and arranged to cooperate with the edges of the tongue in the progressive infolding of the fabric strip as it passes through the channel.

6. A fabric strip folder according to claim 5 in which additional means are provided for rotating said tongue about said axis for adjusting the position of one portion of the tongue to limit movement of the tongue toward the channel bottom surface while permitting a limited range of movement of the tongue portion away from the channel bottom surface.

7. A fabric strip folder for use with a sewing machine, said folder having an inlet and an outlet and comprising a longitudinally extending channel having a bottom surface and a .pair of integral, upstanding coextensive walls continuously rising from said bottom surface; a longitudinally extending tongue pivotally mounted near the folder inlet between the channel walls on an axis transverse thereto, said tongue having longitudinal edges around and about which the opposed edges of a fabric strip in passing through the channel may be progressively infolded; a pair of independently yieldable fingers extending longitudinally in the channel, said fingers being shaped and arranged to coperate with the edges of the tongue in the progressive infolding of the fabric strip as it passes through the channel; and means for simultaneously adjusting the position of both of said fingers in the channel with respect to said tongue.

8. A fabric strip folder according to claim 7 in which openings are provided in the channel bottom surface into which portions of said fingers are received, said openings being of suflicient size to permit limited lateral movement of each of the fingers transversely of the channel.

References Cited by the Examiner UNITED STATES PATENTS Re. 7,985 12/77 Bosworth 112140 X 803,400 10/05 Conley 242-752 X 2,025,531 12/35 Seaman 112140 X 2,130,198 9/38 Seaman 112--140 X 2,769,415 11/56 Sigoda 112140 2,801,602 8/57 Sigoda et a1 112140 3,125,972 3/64 Blumenkrantz et a1. 112-147 X JORDAN FRANKLIN, Primary Examiner. ROBERT V. SLOAN, Examiner. 

1. AN ATTACHMENT FOR A SEWING MACHINE FOR THE PRODUCTION OF BLINDSTITCHING IN CONJUNCTION WITH THE STITCHFORMING AND FEED MECHANISMS OF THE SEWING MACHINE, SAID SEWING MACHINE HAVING A PRESSER FOOT-BAR, SAID ATTACHMENT COMPRISING: A SHANK PORTION ADAPTED TO BE MOUNTED ON THE PRESSER FOOT-BAR, SAID SHANK PORTION HAVING A LARGE OPENING OR WINDOW PROVIDED THEREIN; A CARRIER MOVABLY MOUNTED ON THE SHANK PORTION FOR POSITIONAL ADJUSTMENT WITH RESPECT TO THE STITCHFORMING MECHANISM WHEN THE ATTACHMENT IS MOUNTED ON THE PRESSER FOOTBAR; MEANS ASSOCIATED WITH SAID CARRIER FOR DEMOUNTABLY SUPPORTING ONE OF A SERIES OF DIFFERENT CAPACITY FOLDERS ON THE CARRIER; MEANS ASSOCIATED WITH SAID CARRIER FORSUPPORTING FOR QUICK DETACHMENT ONE OF A SERIES OF DIFFERENT SIZED BLINDSTITCH-NOSED SHOES; EACH OF SAID FOLDERS WHEN SUPPORTED BY SAID CARRIER BEING MOVABLE THEREWITH TO PASS FREELY THROUGH THE WINDOW IN THE SHANK PORTION, AND EACH OF SAID SHOES WHEN SUPPORTED BY SAID CARRIER BEING MOVABLE THEREWITH, SAID FOLDER AND SAID SHOE BEING ARRANGED IN FIXED ADJACENCY WHEN MOUNTED ON THE CARRIER WHICH ADJACENCY IS NOT AFFECTED BY ANY SUBSEQUENT POSITIONAL ADJUSTMENT OF THE CARRIER WITH RESPECT TO THE STITCHFORMING MECHANISM WHEN THE ATTACHMENT IS MOUNTED ON THE PRESSER FOOT-BAR. 